In exchange for the release of four American prisoners, the Obama administration agreed to free seven Iranians in US custody and stop trying to arrest 14 others, two of whom the US government had accused of funneling weapons to the Bashar al-Assad regime and Hezbollah in Syria.

For years, Iran’s privately-owned Mahan Air has been using its planes to bring soldiers and arms directly to the Syrian military and the Lebanese terrorist group Hezbollah by flying them from Tehran to Damascus, according to the US Treasury Department.

According to the Iranian state media organization FARS, Arabnejad is one of the 14 Iranians who no longer will have Interpol red notices out on them, which are meant to ensure their arrest and extradition to the United States on charges that will now also be dropped. The executive order he is sanctioned under is for support for terrorism.

In 2011, the United States sanctioned the entire airline for ferrying personnel and arms for the Revolutionary Guards Corps and Hezbollah, which it officially considers a terrorist organization. The White House declined my request for comment on whether Arabnejad was among the de-listed Iranians, but did not dispute the 14 names on the FARS list.

A 2012 press release from the Treasury says, “Iran used Iran Air and Mahan Air flights between Tehran and Damascus to send military and crowd-control equipment to the Syrian regime.”

Hezbollah and the Assad government coordinate with Mahan Air during their attacks on Syrian civilians and opposition groups, the Treasury Department said.

According to the Iranian news service, another Iranian who will no longer have to look over his shoulder when traveling around the world is Gholamreza Mahmoudi, also a top official at Mahan Air. When Treasury sanctioned Mahmoudi in 2012, it said he worked closely with Arabnejad to evade sanctions and purchase new aircraft.

Last May, as the Iranian nuclear deal was being finalized, Mahan Air was able to purchase nine used Airbus commercial airliners, taking advantage of a relaxation of sanctions that came with an interim agreement Iran struck with Western powers. Experts say that the new lifting of the Interpol “red notices” — essentially arrest warrants — on Arabnejad and Mahmoudi further reduces pressure on Mahan Air and, by extension, on the Assad regime and Hezbollah, even though their Treasury Department sanctions remain in place.

A US official told me Saturday that the United States removed any Interpol red notices and dismissed any charges against 14 Iranians for whom it was assessed that extradition requests were unlikely to be successful.

President Obama spoke about the Iran prisoner swap Sunday and said none of the seven released Iranians was charged with terrorism or any violent offenses. “They are civilians,” he said. But Obama didn’t mention the 14 who no longer have international arrest warrants, including the Mahan Air executives.

The administration has repeatedly said that the Iran nuclear deal and the prisoner swap were separate events, pursued through parallel tracks of diplomacy. But there’s concern on Capitol Hill that the effort to stop the Revolutionary Guards Corps’ violent activities is suffering in the wake of the nuclear agreement.

“This flawed deal is only entrenching Iran’s military and security forces that run the country. Now more than ever, we need a policy of backbone, not backing down,” House Foreign Affairs Committee chairman Ed Royce said Saturday.

On the other hand, Treasury did go forward Sunday with sanctions on Iran’s ballistic-missile program that had been delayed because of the prisoner negotiations.

The return of the American prisoners, including Washington Post reporter Jason Rezaian, is of course good news, and the Obama administration believes the costs of the trade were worth the benefits. But some of those costs could be felt by the Syrian people, who had no say in the trade, got nothing from it and are still begging for more international support to stop Assad’s slaughter of civilians.

Josh Rogin is a Bloomberg View columnist writing about national security and foreign affairs.